Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5749252 | Environmental Pollution | 2017 | 11 Pages |
â¢The PCBs are the major organic compounds found in bottlenose dolphins of LFK and FCE.â¢The PCB concentrations are higher in dolphins from LFK than FCE.â¢The LFK and FCE dolphins have lower PCB levels than in previously published data.â¢The Σ DL PCBs are the major contributor to the dioxin like compound sum.â¢The T-Hg concentrations in FCE dolphins are the highest recorded.
The bottlenose dolphin (Tursiops truncatus) is an upper trophic level predator and the most common cetacean species found in nearshore waters of southern Florida, including the Lower Florida Keys (LFK) and the Florida Coastal Everglades (FCE). The objective of this study was to assess contamination levels of total mercury (T-Hg) in skin and persistent organic pollutants (PCBs, PBDEs, DDXs, HCHs, HCB, Σ PCDD/Fs and Σ DL-PCBs) in blubber samples of bottlenose dolphins from LFK (n = 27) and FCE (n = 24). PCBs were the major class of compounds found in bottlenose dolphin blubber and were higher in individuals from LFK (Σ 6 PCBs LFK males: 13,421 ± 7730 ng gâ1 lipids, Σ 6 PCBs LFK females: 9683 ± 19,007 ng gâ1 lipids) than from FCE (Σ 6 PCBs FCE males: 5638 ng gâ1 ± 3627 lipids, Σ 6 PCBs FCE females: 1427 ± 908 ng gâ1 lipids). These levels were lower than previously published data from the southeastern USA. The Σ DL-PCBs were the most prevalent pollutants of dioxin and dioxin like compounds (Σ DL-PCBs LFK: 739 ng gâ1 lipids, Σ DL-PCBs FCE: 183 ng gâ1 lipids) since PCDD/F concentrations were low for both locations (mean 0.1 ng gâ1 lipids for LFK and FCE dolphins). The toxicity equivalences of PCDD/Fs and DL-PCBs expressed as TEQ in LFK and FCE dolphins is mainly expressed by DL-PCBs (81% LFK - 65% FCE). T-Hg concentrations in skin were significantly higher in FCE (FCE median 9314 ng gâ1 dw) compared to LFK dolphins (LFK median 2941 ng gâ1 dw). These concentrations are the highest recorded in bottlenose dolphins in the southeastern USA, and may be explained, at least partially, by the biogeochemistry of the Everglades and mangrove sedimentary habitats that create favourable conditions for the retention of mercury and make it available at high concentrations for aquatic predators.
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